Shift register is a register with shift function, the data is input to the device in parallel or serial way, and under the action of the clock signal, the data is shifted left or right in order to output at the output end. Logic chips commonly used models: 2003 series, 74 hc595 are needed, HEF4069, 74 ls, KID65004AF, KIA393F, HEF40106BT, SN74LVC1G18YZPR, LM293ADR, TD62003AP, MC74HC164A